Creating Custom hotkey for 'show_wire'
Assuming you just want to toggle Wireframe View on the selected Object, you need a different context for the hotkey. 

Since what you want to influence is a Checkbox that would be wm.context_toggle

In the Context Attributes Field that will appear when you set this, just paste the Data Path that you copied from the Checkbox, in our case object.show_wire 

This should look something like that: